how to fix P0420 code on Ford Explorer Fifth Generation (2011-2019)

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Ensure the vehicle is parked on a level surface and the parking brake is engaged.
• Disconnect the battery to avoid electrical shorts.

2. Inspect and Replace Oxygen Sensors

1. Locate the Oxygen Sensors: Identify the upstream and downstream oxygen sensors connected to the catalytic converter.
2. Remove the Oxygen Sensors: Use an oxygen sensor socket to carefully unscrew and remove both sensors.
3. Inspect Sensor Condition: Check for carbon buildup or damage. Replace if necessary.
4. Install New Sensors: Apply anti-seize compound on the threads of the new sensors and install them securely, ensuring they are not over-tightened.

3. Examine and Replace Catalytic Converter (if necessary)

1. Remove Exhaust Components: If the catalytic converter is faulty, unbolt and remove any exhaust components that may obstruct access, such as the exhaust pipe and heat shields.
2. Remove the Catalytic Converter: Unscrew the bolts securing the catalytic converter to the exhaust system and carefully remove it.
3. Install New Catalytic Converter: Position the new catalytic converter in place, aligning it with the exhaust system. Secure it with the appropriate bolts, tightening to the manufacturer's torque specifications.
4. Reinstall Removed Components: Reattach any exhaust components or heat shields that were removed.

4. Final Checks

1. Reconnect Battery: Reconnect the battery terminals.
2. Clear Codes: Use an OBD-II scanner to clear the P0420 code from the system.
3. Test Drive the Vehicle: Drive the vehicle under various conditions to ensure the check engine light does not reappear.